This invention relates to water heaters and more particularly to direct contact water heaters.
Direct contact water heaters, such as that disclosed in U.S. Pat. No. 4,574,775 comprise, a vertically oriented cylindrical column having a plurality of heat exchange bodies disposed adjacent its upper end and a spray nozzle located above the heat exchange bodies for spraying water to be heated downwardly thereon. A combustion chamber for containing a burner extends through an opening in the column and below the heat exchange bodies for injecting heated combustion products inwardly into the column. The hot gases pass upwardly through the heat exchange bodies located in the upper end of the column and are then exhausted. The water discharged from the nozzle flows downwardly over the heat exchange bodies and through the heated combustion products.
In one type of prior art direct contact water heater, a water jacket is disposed within the column and surrounds at least that portion of the column which defines the combustion chamber. A portion of the feed water is delivered to the lower end of the water jacket from where it flows upwardly between the water jacket and the column and discharges from the upper end of the water jacket to be mixed with the water delivered from the spray nozzle.